Ethyl L-threoninate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007.08.28 - 2007.08.30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for Testing of Chemical No. 202 "Daphnia sp., Acute Immobilisation Test". ISO InternationalStandard 6341: Water Quality-Determination of the inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea).

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: 0706H016

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: -20ºC
- Stability under storage conditions: stable when stored at -16ºC to -25ºC

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Melting point: 50-55°C
- Boiling point: 180.7-202.1°C
- Water solubility (under test conditions): > 4,000 g/L (20ºC)
OTHER PROPERTIES (if relevant for this endpoint)
- Results of test for ready biodegradability: 97+/-3% of the ThOD after 28 days

Analytical monitoring:

yes

Remarks:

The TOC analyses were not carried out in compliance with the OECD GLP principles

Details on sampling:

- - Concentrations: control (0mg/L) and highest test concentration (2,000mg/L)
- Sampling method: The actual test concentrations were verified by a chemical analysis of the Total Organic Carbon (TOC) content in the test solutions. At the initiation of the test, at renewal of the test solutions
after 24 hours (new and old solutions) and after 48 hours (old solutions), 2 × 8-10-mL subsamples of each test solution were collected for chemical analysis of TOC.

Vehicle:

no

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: The test substance was dissolved in test medium. The test medium was prepared from Millipore water according to ISO 6341 standard.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name:Daphnia magna Strauss.
- Strain:(Cladocera, Crustacea)
- Source: Collected in Langedam, Birkerød,and cultured at DHI since 1979
- Age at study initiation (mean and range, SD): <24h
- Method of breeding: not stated
- Feeding during test: No
- Food type: NA
- Amount: NA
- Frequency: NA

ACCLIMATION
- Acclimation period: No (daphnids < 24h applied in the study)

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

24 and 48 h

Hardness:

CA 250 mg CaCO3/L

Test temperature:

19.5 ± 0.3°C (measured)

pH:

7.7-7.8 (measured)

Dissolved oxygen:

96-100 % (measured)

Salinity:

NA

Nominal and measured concentrations:

Nominal
concentration
(mg/L) Sampling time Theoretical content of organic carbon Average measured content of organic carbon
(mg TOC/L) (mg TOC/L)
2,000 0 hours new 979 992
2,000 24 hours old 979 488
2,000 24 hours new 979 957
2,000 48 hours old 979 431

Details on test conditions:

TEST SYSTEM
- Test vessel: The test was carried out in 50-mL glass containers
- Material, size, headspace, fill volume: 25 mL of test solution
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): NA
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): NA
- Biomass loading rate: No data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: No data
- Culture medium different from test medium:no
- Intervals of water quality measurement: The pH and dissolved oxygen were measured at 0, 24 (before and after renewal) and 48 hours. No information on other parameters meassured
OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: Test was run in the dark
- Light intensity: NA

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
Range finding study: No
- Test concentrations: 0 (control); 50; 100; 200; 500; 1,000 and 2,000 mg/L.
- Results used to determine the conditions for the definitive study: No data

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 2 000 mg/L

Nominal / measured:

nominal

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

>= 1 460 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

other: TOC-analysis

Details on results:

In order to verify the actual test concentrations throughout the test, samples were collected for chemical analysis. At the initiation of the test, at renewal of the test solutions after 24 hours (new and old solutions) and after 48 hours (old solutions), duplicate 8-10-mL samples were taken from the test solutions for analysis of the Total Organic Carbon (TOC) content. The concentration of TOC was measured at DHI by use of Dr. Lange ISIS 9000 photometer with test kit LCK 380 (detection range 2.0-65 mg/L TOC). The TOC analyses were not carried out in compliance with the OECD GLP principles
- effect of control: Less than 10 percent of the control animals were immobilized
- Other adverse effects control: none stated
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Not stated
- Effect concentrations exceeding solubility of substance in test medium: No

Results with reference substance (positive control):

EC50 = 1.77 mg/L [1.57-2.02] (immobility)

Reported statistics and error estimates:

Probit analysis. Version 2.3, 1990.03.20.

No

Validity criteria fulfilled:

yes

Conclusions:

There was no acute effect of L-TEE from 0 to 1,460 mg/L (estimated actual concentration) and thus, the estimated EC values were: EC10 and EC50
(48 hours) >1,460 mg/L (estimated actual concentration) based on TOC analysis.

Executive summary:

The test substance L-TEE was tested according to the OECD Guideline No. 202 which is further specified in the ISO International Standard 6341. L-TEE was tested at the following nominal concentrations:

0 (control); 50; 100; 200; 500; 1,000 and 2,000 mg/L.

In order to verify the actual test concentrations throughout the test, samples were collected for chemical analysis. At the initiation of the test, at renewal of the test solutions after 24 hours and at the end of the test, samples were taken for analysis of Total Organic Carbon (TOC). The test results can be summarised as follows:

• The analysis of TOC showed that all of the test substance was dissolved in the test medium as the recovery was 101% (992 mg TOC/L) at t = 0 hours and 98% (957 mg TOC/L) at t = 24 hours, i.e. >80% of the theoretical content of L-TEE (979 mg TOC/L) immediately after preparation. However, the decay of substance was quite significant as only 50% and 44%, respectively, were present after 24 hours of exposure. The statistical treatment of the results and the calculation of EC values was thus based on the TOC analysis from t = 0 hours to t = 24 hours and again from t = 24 hours to t = 48 hours. The highest tested concentration was 2,000 mg/L (nominal), which was equivalent to the highest estimated actual concentration, 1,460 mg/L (73% of 2,000 mg/L).

• There was no acute effect of L-TEE from 0 to 1,460 mg/l (estimated actual concentration) and thus, the estimated EC values were: EC10 and EC50 (48 hours) >1,460 mg/L (estimated actual concentration) based on TOC analysis.

Description of key information

There was no acute effect of L-TEE from 0 to 1,460 mg/L (estimated actual concentration) and thus, the estimated EC values were: EC10 and EC50

(48 hours) >1,460 mg/L (estimated actual concentration) based on TOC analysis.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1 460 mg/L